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<head>
    <meta charset="UTF-8">
    <title>CSS3基本选择器</title>
    <style>
        h1{
            color: #090;
        }

        p{
            font-size:18px;
            color:red;
        }

        .blue{
            font-size:18px;
            color:yellow;
        }
        #title{
            font-size:18px;
            color:orange;
        }

        #black{
            color:rgb(0,0,0);
            font-weight: bold;
        }
    </style>
</head>
<body>
<h1>静夜思</h1>
<h2 id="title">作者：李白</h2>
<p>床前明月光，疑是地上霜。</p>
<p class="blue" id="black">举头望明月，低头思故乡。</p>
</body>
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